The aim of this study was to investigate the effects of sitagliptin/metformin (sitaformin), metformin and sita- gliptin in PCOS patients. PCOS is a hormonal disorder and therefore the use of treatments that modulate hormone levels Like AMH, testosterone, insulin, leptin and especially FAI and HOMA-IR can reclaim the symptoms of PCOS. PCOS also increases oxidative stress and lipid peroxidation. Therefore, in clinical and research trials, the level of these factors is usually examined to reduce patients’ symptoms. Participants were randomly assigned to receive metformin, sitagliptin, sitaformin or placebo Treatment was carried out 2 months before the start of the ovulation cycle and continued until the day of ovum pick up. The serum levels of HOMA-IR and FAI decreased significantly in the treated groups compared to the placebo. The serum and the FF levels of leptin also decreased significantly in the sitaformin group when compared to the metformin and sitagliptin groups. Moreover, the serum and FF levels of AMH and MDA had a significant decrease in the sitaformin and sitagliptin group compared to the placebo. The mRNA expression and protein levels of GDF9 and BMP15 in the cumulus cells increased significantly in the sitaformin compared to metformin and sitagliptin groups. The expression level of GDF9 and BMP15 mRNA were positively correlated with the fertilization rate and grade I embryos. Sitaformin improves levels of GDF9 and BMP15 in PCOS compared to metformin and sitagliptin, which can increase the rate of fertilization and grade I embryos.